He said the equity fund returned 2 per cent in 2010 while the commodity fund shed 15 per cent. Pickens declined to give a specific number for either fund so far in 2011, but described the performance of both as 'very good indeed'.

Pickens is a long-term advocate of the United States switching to natural gas as a transportation fuel and reducing its reliance on imported oil, especially from the Middle East.

He has frequently said the US government lacks a long-term energy strategy, despite being the world's largest oil consumer, and cautioned oil prices could triple in the next 10 years without one.

'Where else in the world doesn't have an energy plan,' Pickens said.

'If we don't do something to reduce our reliance on imported oil, we could see $300 a barrel in the next decade.'

The US consumes over 19 million barrels of oil a day, around 22 per cent of the global total, according to the US Department of Energy. – Reuters